.center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
.left {
  float: left;
}
.right {
  float: right;
}
.cls {
  clear: both;
}
a {
  text-decoration: none;
}
ul,
li,
dl,
dt,
dd,
ol {
  list-style: none;
}
